Hip Joint - Anatomy Pictures and Information Hip Joint Home > Skeletal System > Bones of the Leg and Foot > Hip Joint Hip Joint The hip joint is one of the most important joints in the human body. It allows us to walk, run, and jump. It bears our body’s weight and the force of the strong muscles of the hip and leg. Yet the hip joint is also one of our most flexible joints and allows a greater range of motion than all other joints in the body except for the shoulder. The hip joint is a ball-and-socket synovial joint formed between the os coxa (hip bone) and the femur. A round, cup-shaped structure on the os coax, known as the acetabulum, forms the socket for the hip joint. The rounded head of the femur... Move up/down/left/right: Click compass arrows Rotate image: Click and drag in any direction, anywhere in the frame Identify objects: Click on them in the image 2D Interactive 3D Rotate & Zoom Change Anatomical System Full Hip Joint Description [Continued from above] . . . forms the ball of the joint.

Hyaline cartilage lines both the acetabulum and the head of the femur, providing a smooth surface for the moving bones to glide past each other. Hyaline cartilage also acts as a flexible shock absorber to prevent the collision of the bones during movement. Between the layers of hyaline cartilage, synovial membranes secrete watery synovial fluid to lubricate the joint capsule. Surrounding the hip joint are many tough ligaments that prevent the dislocation of the joint. The strong muscles of the hip region also help to hold the hip joint together and prevent dislocation. Functionally, the hip joint enjoys a very high range of motion. The ball-and-socket structure of the joint allows the femur to circumduct freely through a 360-degree circle. The femur may also rotate around its axis about 90 degrees at the hip joint. Only the shoulder joint provides as high of a level of mobility as the hip joint. In addition to being flexible, each hip joint must be capable of supporting half of the body’s weight along with any other forces acting upon the body.

During running and jumping, for example, the force of the body’s movements multiplies the force on the hip joint to many times the force exerted by the body’s weight. The hip joint must be able to accommodate these extreme forces repeatedly during intense physical activities. If a knee or hip joint breaks in an accident or wears out in old age, a surgeon can replace it with a ball-and-socket joint made from metal and plastic and engineered in such a way that it will duplicate the motions of a human joint. Hip replacement was once impossible because, although joints could easily be produced in a laboratory, the human body rejected the materials. Sometimes the pins that held the artificial joint to other bones worked loose and required further surgery. Some joints, especially the artificial knee, didn't work very well because they were designed like hinges that just opened one way. Later, when the designers realized the knee needed to rotate slightly, they produced a joint that would fulfill these movements as well. Medical pioneers finally overcame bodily rejection by making the joints out of non-irritating, man-made materials. Surgeons have now perfected hip and knee replacement surgeries so that recipients are relieved of pain and can walk at a smoother pace.

Prepared by Tim Taylor, Anatomy and Physiology Instructor What kind of joint is the hip? - Functions of Joints - Sharecare Functions of Joints What kind of joint is the hip? A Dr. Mehmet Oz, MD , Cardiology (Cardiovascular Disease), answered The hip is a ball and socket joint. As such, a normal hip joint has a wide range of motion. A rounded ball of bone at one end of the thighbone, or femur, moves or articulates inside a cup-like socket that is part of the pelvis. Helpful? This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs. Videos (6) Functions of Joints Joints connect bones within your body, bear weight and enable you to move. They are made up of bone, muscles, synovial fluid, cartilage and ligaments. Joints aren't all alike, however. Hinge joints are found in your elbows and knees, while ball-and-socket joints are needed for the hips and shoulders. Different joints provide unique points of stability and mobility.

Understanding the functions of your joints and how your lifestyle and overall health affect them can help if you develop conditions like arthritis, osteoarthritis or gout. Functions of Joints Q&As Dissector Answers - Joints of the Lower Limb Dissector Answers - Joints of the Lower Limb Learning Objectives and Explanations: 1. List and describe the various types of moveable joints and give examples of each type. (W&B 46-51, M 21-26) The three major types of joints, along with subtypes and examples, are listed here: Fibrous joints: the most simple joints. They are only connected by fibrous ligaments. A suture is a fibrous joint that eventually fuses, forming one bone from two (a synostosis), like in the skull of a growing infant. A gomphosis is the joint between a tooth and the jaw. A syndesmosis is a fibrous membrane or ligament that joints two bones. The tibia and fibula have an interosseous ligaments or membrane, as do the radius and ulna. Cartilaginous joints: joined by cartilage only.

These joints are avascular or anervous, except at their margins. Synchondroses are temporary joints present in growing bones. The epiphyseal plate (growth plate) will later ossify into solid bone. The epiphysis has hyaline cartilage and the extension of ossification from the diaphysis side converts it to bone. A symphysis is a permanent cartilaginous union. They always have hyaline cartilage on the bony surfaces concerned, and these cartilaginous surfaces are joined by fibrous tissue or fibrocartilage. Synovial joints: "diarthroses" (freely moveable joints). These joints are joined by a fluid-filled capsule and accessory ligaments. Examples include the knee, ankle, and hip. 2. List the characteristics of and identify the parts of a typical synovial joint. (W&B 47-49, M 23-26) Synovial joints consist of: Hyaline cartilage: covers the full weight-bearing surface, providing a smooth yet resilient surface Joint capsule: a cavity, made of accessory ligaments, with synovial fluid inside. This reinforces the synovial membrane.

Synovial membrane lining: secretes synovial fluid and covers the synovial cavity. It reaches to the edges of the hyaline cartilage. Accessory structures: accessory ligaments ("intracapsular" and "extracapsular"); articular discs or menisci, which are pads of fibrous cartilage; muscles and tendons; and subsynovial fat. Types of synovial joints Plane: involves flat surfaces. Movements consist of sliding of one surface on the other, and may be multidirectional in one plane. Examples: facet joints, joints of the tarsal bones of foot. Hinge (ginglymus): movement around a single axis at right angles to the bone. Permits flexion and extension only. These usually have strong collateral ligaments on each side reinforcing the joint. Examples: elbow, knee. Pivot (trochoid): rotary movement around a longitudinal axis. Rounded process of bone rotates within a sleeve or ring composed of a bony fossa and a strong ligamentous band. Examples: atlas-axis, radioulnar joint. Condyloid: oval surfaces allowing movements in two planes at right angles to each other.

Example: radiocarpal joint Saddle (sellar): movement in two basic axes, with circumduction. Example: carpal-metacarpal joint of the thumb. Ball and socket: allows movement in any axis. Examples: hip, shoulder. 3. Recall the movement characteristics of the various types of synovial joints. (W&B 47-49, M 23-26) See #2 above. 4. Describe the structure of the joints of the lower limb and the functional capabilities and limitations of each based on their bony structure and ligaments. (W&B 633-640, 642-644, M 607-613, 617-625, 632-635) Images from "Anatomy of the Human Body" by Henry Gray are provided by: The hip joint is a ball and socket type of joint. The femoral head is the ball, while the acetabulum is the socket. It is the second most movable joint in the body, with only the shoulder having greater range of motion. This joint is not only flexible, but strong by necessity.

During standing, the entire weight of the body is transferred to the head and neck of the femur. The acetabular labrum helps provide this strength by grasping more than half of the head of the femur. (Latin, acetabulum = vinegar cup) The main ligaments of the hip joint are really thickenings of the fibrous capsule, which is attached to the acetabulum and transverse acetabular ligament. Some deep fibers pass circularly around the neck forming the zona orbicularus. These fibers form a collar around the neck that constricts the capsule and helps hold the femoral head in the acetabulum. This fibrous capsule does not attach to the posterior aspect of the femur. (This creates a possibility for dislocation backward, say, if your knees hit the dashboard of a car that, with the assistance of a tree, makes a sudden stop.) As the thigh becomes fully extended, the capsule is twisted and shortened, and the head of the femur is guided like a screw into its socket. Stability is at a maximum with hyperextension and at a minimum with flexion. (That is another reason why the femur gets pushed posteriorly with a car accident.

The victim is sitting with the hip in a flexed, less stable position.) The four ligaments of the joint, listed below, allow considerable flexion of the hip joint, but restrict extension of the joint to 10 to 20 degrees beyond the vertical position. iliofemoral ligament: Y-shaped. It prevents hyperextension of the hip joint during standing by screwing the femoral head into the acetabulum. pubofemoral ligament: prevents overabduction of the hip joint. ischiofemoral ligament: It also screws the femoral head medially into the acetabulum, preventing hyperextension of the hip joint. This ligament also forms the posterior free margin of the capsule. ligament of the head of the femur: weak and of little importance in strengthening the hip joint. Images from "Anatomy of the Human Body" by Henry Gray are provided by: The knee joint is basically a hinge type of joint, allowing flexion and extension. The hinge movements are combined with some gliding and rolling and with some rotation about a vertical axis. This allows free motion in one primary plane combined with decent stability.

The fibrous capsule is deficient in a few areas to allow tendons to pass through to the outside. The synovial membrane lines the fibrous capsule and attaches to the periphery of the patella and the edges of the menisci. (Latin, patella = shallow dish, Greek, meniskos = moon, crescent). It reflects onto the cruciate ligaments and also reflects between the tibia and fibula, covering the infrapatellar fat pad. This technically separates the fat pad and the cruciate ligaments from the joint cavity. The knee joint is relatively weak and depends on several things to strengthen it. First, its area of weight distribution is two or three times larger than either the tibia or the femur, which reduces the overall pressure. Furthermore, a strong fibrous capsule, the medial patellar and lateral patellar retinacula, patellar tendon, iliotibial tract (lateral side), and longitudinal fibers of fascia lata (medial side) all serve to strengthen the joint. Finally, two groups of important ligaments help add stability: collateral ligaments: capsular and extracapsular. They become taut in extension and prevent hyperextension, also prevent abduction and adduction.

The medial collateral ligament, at its midpoint, firmly attaches to the medial meniscus. It is the weaker of the two, so injuries are more common here and, moreover, will usually involve the medial meniscus. The lateral collateral ligament is separated from the lateral meniscus by the tendon of the popliteus. Other extracapsular ligaments that strengthen the knee are the patellar ligament, the oblique popliteal ligament and the arcuate popliteal ligament. cruciate ligaments: intracapsular. The anterior cruciate ligament (ACL) is weaker than the posterior cruciate ligament (PCL). They both prevent movement of the tibia forward or backward under the femoral condyles. They become taut in all positions of flexion but mostly with full extension and full flexion. (cruciate = cross-shaped) Images from "Anatomy of the Human Body" by Henry Gray are provided by: The ankle joint is a hinge type of synovial joint. It is located between the distal ends of the tibia and fibula and the superior part of the talus.

The distal ends of the tibia and fibula form a deep socket into which the trochlea of the talus fits. (Latin, trochlea = block of pulleys, from Greek, trochos = wheel) The tibia itself articulates with the talus in two places: the inferior surface and medial malleolus of the tibia. The medial malleolus grips the talus tightly during movements of the joint. This grip is strongest during dorsiflexion because the anterior part of the talus is wider than the posterior, and that wide section is forced into the joint. Plantar flexion is relatively unstable and most injuries occur then. The lateral malleolus of the fibula also articulates with the talus. The ankle joint has less range of movement than the knee or the hip, so there are fewer supporting structures needed.

The fibrous capsule is supported on each side by strong collateral ligaments The lateral ligament is composed of three parts: anterior talofibular ligament: a flat, weak band posterior talofibular ligament: a thick, fairly strong band calcaneofibular ligament: a round cord The medial ligament has four parts, but you only need to know it as the deltoid ligament. It stabilizes the ankle during eversion and prevents subluxation (partial dislocation) of the joint. (deltoid = shaped like a delta... the Greek letter) 5. Describe the blood and nerve supply of the joints and in particular the effect of interruption of blood to the head and neck of the femur. (W&B 634, 640, M 613-614, 626, 636) Hip: Blood Supply: medial and lateral circumflex femoral arteries: these are usually branches of the deep femoral artery, but sometimes they are branches of the femoral artery itself. The medial branch supplies the most blood. artery to the head of the femur: a branch of obturator artery.

It enters the joint through the ligament of the head of the femur. Nerve Supply: femoral nerve and branches: anteriorly accessory obturator nerve: if present, anteriorly obturator nerve, anterior division: inferiorly superior gluteal nerve: superiorly and posteriorly nerve to quadratus femoris: posteriorly Knee: Blood Supply: genicular branches of femoral artery: contribute to genicular anastomosis popliteal branches, anterior recurrent, and posterior recurrent branches of the anterior tibial recurrent and circumflex fibular arteries: contribute to genicular anastomosis middle genicular branches of popliteal artery: penetrate the fibrous capsule of the knee joint and supply the cruciate ligaments, synovial membrane, and peripheral margins of the menisci Nerve Supply: branches of the obturator, femoral, tibial and common fibular nerve Ankle: Blood Supply: derived from malleolar branches of the fibular artery and the anterior and posterior tibial arteries Nerve supply: derived from the tibial nerve and the deep fibular nerve 6. Identify and describe the structure and function of the knee joint and in particular the effects of injury to the ligaments and menisci.

(W&B 635-641, M 617-630) The structure and function have been described in #4 above. The possibilities for injury are numerous and often serious. The knee's stability depends almost entirely on its associated ligaments and muscles, yet it must still be mobile, making it very prone to injury. Below are the most common injuries: tibial collateral ligament: caused by a blow to the lateral side of the knee. Since the tibial collateral ligament is firmly attached to the medial meniscus, tearing it frequently results in concomitant tearing of the meniscus. Furthermore, in many cases there is also trauma to the ACL, resulting in the "terrible triad", which is common in football. medial meniscus: can also be damaged independently by "twisting strains". (The lateral meniscus is hardly ever injured.) Small tears will heal themselves, but if the tear is large enough, the torn part of the meniscus can be removed with no loss of mobility. However, the tibial plateaus often undergo inflammation. These injuries are especially common in football and volleyball.

anterior cruciate ligament: severe force to the anterior knee can cause a tear of the ACL. This causes the tibia to be able to slide anteriorly from the femur, which is diagnostic as the "anterior drawer sign". Skiing accidents are an example of a frequent cause of ACL tears. posterior cruciate ligament: ruptures when a player lands on the tibial tuberosity with the knee flexed. This is usually in conjunction with tibial or fibular collateral ligament tears. It is diagnosed with the "posterior drawer sign". These injuries are pretty common in basketball, and can also happen in head-on collisions when seatbelts are not worn. 7. Identify the structure of the ankle and foot joints and describe how the joints and ligaments provide firm footing but flexibility of movement. (W&B 642-652, M 632-645) The structure of the ankle joints have been described in #4 above.

The following are the structures of the foot joints, as described in the session on the foot: Joints: The subtalar joint is formed between the large concave facet on the under surface of the body of the talus and the convex posterior articular surface on the superior aspect of the calcaneus. A loose, thin walled articular capsule unites the two bones by attaching to the margins of the articular surfaces. This joint allows the foot to be placed firmly on slanting and irregular surfaces.The transverse tarsal joint is the designation for the irregular plane which extends from side to side across the foot and is composed of the talonavicular articulation medially and the calcaneocuboid joint laterally. This joint allows inversion and eversion of the foot. Ligaments: The plantar ligaments of the joints of the foot are very strong. They they are supplemented by robust interosseous ligaments which keep the bones from spreading apart. Notable on the sole of the foot are the long plantar ligament and the plantar calcaneocuboid and plantar calcaneonavicular ligaments.

The elasticity of the latter and its support of the head of the talus have led to it being called the "spring ligament." The plantar aponeurosis may be likened to a "tie rod" for the longitudinal arch, firmly connecting its ends and preventing their spread. 8. Describe the arches of the foot and how the bony structure and ligaments form and support them. There are two longitudinal arches, medial and lateral. They pass from the calcaneus to the talus to the navicular to the cuneiforms to the metatarsals. They are supported by the plantar calcaneonavicular ligament (spring ligament), and also by the tendons of the tibialis anterior and tibialis posterior muscles. The transverse arch results from the shape of the distal row of tarsal bones and the bases of the metatarsal bones. Imagine an arch that goes over the top of the cuneiforms and cuboid, and is supported by the shape of the bones, various ligaments, and the tendons of the fibularis longus, tibialis anterior, and tibialis posterior muscles.

Cultural enrichment: Check out these sections from the 1918 version of Gray's Anatomy of the Human Body ! Some of the terms are (of course) out-of-date, but the illustrations are timeless. Questions and Answers: 9. What contacts the articular (medial) surface of the lateral malleolus? The medial side of the lateral malleolus, which is part of the fibula, articulates with the lateral surface of the talus. 10. Note the iliopectineal bursa beneath the iliopsoas. Does it communicate with the hip joint? The iliopectineal bursa lies between the iliopsoas muscle and the capsule. When the capsule is perforated here, the bursa is open to the joint cavity. 11. Trace the obturator externus tendon beneath the neck of the femur into the trochanteric fossa. What is its action and innervation? The obturator externus muscle is involved in lateral rotation of the thigh, as is the obturator internus muscle. It also stabilizes the head of the femur. The obturator externus muscle is innervated by the obturator nerve. 12.

What is the importance of the blood supply to the articulations involving the zona orbicularis, the acetabular labrum, the transverse ligament and the ligamentum capitis femoris (ligament of the head of the femur)? There is no collateral supply really available for the head of the femur or the parts around it. The main blood supply comes from the lateral, and especially the medial, circumflex femoral arteries. If the medial circumflex femoral artery is damaged, the small artery of the ligament of the head is not sufficient, and avascular necrosis of the femoral head will occur. 13. What is the difference between the two collateral ligaments in the knee joint? The lateral is stronger and does not attach to the meniscus, while the medial is weaker and does attach to the meniscus. 14. What is the function of the patella? The patella is a large sesamoid bone that developed in the tendon of the quadriceps femoris muscle.

It pushes against the anterior articular surface of the femur's inferior surface, and, by holding the tendon off the lower end of the femur, improves the angle of approach of the tendon to the tibial tuberosity. 15. With what does the patella articulate? See above #14 above. 16. What are the actions of the cruciate ligaments? They stabilize the knee joint by preventing the movement of the tibia forward or backward, with the anterior cruciate ligament preventing anterior displacement and the posterior cruciate ligament preventing posterior displacement. 17. What are the "drawer sign" and the "terrible triad"? The anterior drawer sign, movement of the tibia anteriorly when the flexed leg is pulled anteriorly, indicates anterior cruciate ligament rupture. The posterior drawer sign, movement of the tibia posteriorly when the flexed leg is pushed, indicates posterior cruciate rupture. The terrible triad is a tearing of the medial collateral ligament, the medial meniscus, and the anterior cruciate ligament all at the same time. 18. What does the transverse tibiofibular ligament do? This ligament helps to hold tibia and fibula together.

It also forms a portion of the articulation with talus. 18a. Relate the arrangements of the malleoli and ligaments to the prevalence of ankle sprains. Most ankle sprains are caused by inversion of the foot, which causes tearing of the lateral ligaments: the calcaneofibular and posterior talofibular ligaments. Slight sprains might involve just partial tears, such as in the anterior talofibular ligament. Sometimes the lateral malleolus can be avulsed off the fibula or the fibula fractured if the ligaments are particularly strong. In effect, the ligaments are stronger than the bone, and the bone often "gives" first. The medial ligament is more rarely strained, but when it is it is due to eversion of the foot. 19. How is the stability of the ankle joint provided? See #4 and #7 above. 20. Which position is most stable? Why this position? Dorsiflexion is more stable than plantarflexion. The talus is stabilized due to the wider anterior side of the trochlea being immobilized by the tibial articulation.

In plantarflexion, the skinnier posterior side is articulating more and so more movement is possible since it does not completely fill the space allowed the anterior side. 21. What muscles provide action of the ankle joint? Dorsiflexion: muscles of anterior compartment of leg. These include the tibialis anterior muscle, the extensor hallucis longus muscle, the extensor digitorum longus muscle, and the fibularis tertius muscle. When the foot is fully everted, it is also fully dorsiflexed. (But remember, inversion and eversion are actions of the foot itself. Plantarflexion: muscles of posterior compartment of leg. These include the tibialis posterior muscle, the flexor hallucis longus muscle, the flexor digitorum longus muscle and the plantaris muscle. The lateral compartment also participates in plantar flexion. (In fact, all muscles which enter the foot behind the malleoli plantarflex the foot. When the foot is fully inverted, it is also fully plantarflexed. 22. What muscles provide stability of the ankle joint? All of the muscles mentioned above that cross the ankle lend stability to the ankle.

The ligaments provide the stability as well. See also #4 and #7 above. 23. What is the function of the plantar ligaments dissected? long plantar ligament: maintains the arches of the foot and forms tunnel for the tendon of the fibularis longus by extending some its fibers to the bases of the metatarsals. short plantar ligament: deep to the long plantar ligament. It also provides support of the longitudinal arch. plantar calcaneonavicular (spring) ligament: highly elastic. It completes the socket for the head of the talus bone on the medial side and provides springy cushion for the foot. It also helps maintain the longitudinal arch of the foot. 24. What are the actions of the subtalar articulation? This joint is pretty stiff, though it allows some inversion and eversion. 25. What is the tarsal sinus? It is a cavity lying between the talus and the calcaneus. 26. What is the interosseous talocalcaneal ligament? This ligament is located inside the tarsal sinus.

It is a strong band which connects the adjacent surfaces of the talus and the calcaneus along the oblique tarsal grooves. It provides support for the subtalar joint. 27. What are the two parts and the action of the transverse tarsal joint? It is formed by the combined talonavicular and calcaneocuboid joints. The two separate joints align transversely. (Transection across the transverse tarsal joint is a standard method for surgical amputation of the foot.) Inversion and eversion take place primarily through the transverse tarsal joint. 28. What are the actions of the foot? Dorsiflexion, plantar flexion, inversion and eversion of the foot are the main actions of the foot. Copyright© 2000 The University of Michigan. Unauthorized use prohibited. The Hip Joint - Articulations - Movements - TeachMeAnatomy 4.2 Acquired Dislocation The hip joint is a ball and socket synovial joint, formed by an articulation between the pelvic acetabulum and the head of the femur.

It forms a connection from the lower limb to the pelvic girdle, and thus is designed for stability and weight-bearing – rather than a large range of movement. In this article, we shall look at the anatomy of the hip joint – its articulating surfaces, ligaments and neurovascular supply. Structures of the Hip Joint Articulating Surfaces The hip joint consists of an articulation between the head of femur and acetabulum of the pelvis. The acetabulum is a cup-like depression located on the inferolateral aspect of the pelvis. Its cavity is deepened by the presence of a fibrocartilaginous collar – the acetabular labrum. The head of femur is hemispherical, and fits completely into the concavity of the acetabulum. Both the acetabulum and head of femur are covered in articular cartilage, which is thicker at the places of weight bearing. Fig 1 – The articulating surfaces of the hip joint – pelvic acetabulum and head of the femur. Ligaments The ligaments of the hip joint act to increase stability.

They can be divided into two groups – intracapsular and extracapsular: Intracapsular The only intracapsular ligament is the ligament of head of femur. It is a relatively small structure, which runs from the acetabular fossa to the fovea of the femur. It encloses a branch of the obturator artery (artery to head of femur), a minor source of arterial supply to the hip joint. Extracapsular There are three main extracapsular ligaments, continuous with the outer surface of the hip joint capsule: Iliofemoral ligament – spans between the anterior inferior iliac spine and the intertrochanteric line of the femur. It has a ‘Y’ shaped appearance, and prevents hyperextension of the hip joint Pubofemoral – spans between the superior pubic rami and the intertrochanteric line of the femur. It has a triangular shape, and prevents excessive abduction and extension. Ischiofemoral – spans between the body of the ischium and the greater trochanter of the femur. It has a spiral orientation, and prevents excessive extension.

Neurovascular Supply The arterial supply to the hip joint is largely via the medial and lateral circumflex femoral arteries – branches of the profunda femoris artery (deep femoral artery). They anastomose at the base of the femoral neck to form a ring, from which smaller arteries arise to supply the hip joint itself. The medial circumflex femoral artery is responsible for the majority of the arterial supply (the lateral circumflex femoral artery has to penetrate through the thick iliofemoral ligament). Damage to the medial circumflex femoral artery can result in avascular necrosis of the femoral head. The artery to head of femur and the superior/inferior gluteal arteries provide some additional supply. The hip joint is innervated by the femoral nerve, obturator nerve, superior gluteal nerve, and nerve to quadratus femoris. © 2015-2017 TeachMeAnatomy.com [CC-BY-NC-ND 4.0] Fig 2 – The medial and lateral circumflex femoral arteries are the major blood supply to the hip joint. Stabilising Factors The primary function of the hip joint is to weight-bear.

There are a number of factors that act to increase stability of the joint. The first structure is the acetabulum. It is deep, and encompasses nearly all of the head of the femur. This decreases the probability of the head slipping out of the acetabulum (dislocation). There is a fibrocartilaginous collar around the acetabulum which increases its depth, known as the acetabular labrum. The increase in depth provides a larger articular surface, further improving the stability of the joint. The iliofemoral, pubofemoral and ischiofemoral ligaments are very strong, and along with the thickened joint capsule, provide a large degree of stability. These ligaments have a unique spiral orientation; this causes them to become tighter when the joint is extended. In addition, the muscles and ligaments work in a reciprocal fashion at the hip joint: Anteriorly, where the ligaments are strongest, the medial flexors (located anteriorly) are fewer and weaker. Posteriorly, where the ligaments are weakest, the medial rotators are greater in number and stronger – they effectively ‘pull’ the head of the femur into the acetabulum.

Fig 3 – The extracapsular ligaments of the hip joint; ileofemoral, pubofemoral and ischiofemoral ligaments. Movements and Muscles The movements that can be carried out at the hip joint are listed below, along with the principle muscles responsible for each action: Flexion – iliopsoas, rectus femoris, sartorius Extension – gluteus maximus, semimembranosus, semitendinosus and biceps femoris Abduction – gluteus medius, gluteus minimus and the deep gluteals (piriformis, gemelli etc.) Adduction – adductors longus, brevis and magnus, pectineus and gracillis Lateral rotation – biceps femoris, gluteus maximus, and the deep gluteals (piriformis, gemelli etc.) Medial rotation – gluteus medius and minimus, semitendinosus and semimembranosus The degree to which flexion at the hip can occur depends on whether the knee is flexed – this relaxes the hamstring muscles, and increases the range of flexion.

Extension at the hip joint is limited by the joint capsule and the iliofemoral ligament. These structures become taut during extension to limit further movement. Clinical Relevance: Dislocation of the Hip Joint Congenital Dislocation Congenital hip dislocation is known as developmental dysplasia of the hip (DDH). It occurs when the hip joint does not develop properly in utero. Common clinical features include: Limited abduction at the hip joint Limb length discrepancy – the affected limb is shorter Asymmetrical gluteal or thigh skin folds DDH is usually treated with a Pavlik harness. This holds the femoral head in the acetabular fossa and promotes normal development of the hip joint. Surgery is indicated in cases that do not respond to harness treatment. Acquired Dislocation Acquired dislocations of the hip joint are relatively uncommon, owing to the strength and stability of the joint. They usually occur as a result of trauma. There are two main types of acquired hip dislocation; posterior and anterior: Posterior dislocation – the femoral head is forced posteriorly, and tears through the inferior and posterior part of the joint capsule, where it is at its weakest. The affected limb becomes shortened and medially rotated.

The sciatic nerve runs posteriorly to the hip joint, and is at risk of injury (occurs in 10-20% of cases). Anterior dislocation (rare) – occurs as a consequence of traumatic extension, abduction and lateral rotation. The femoral head is displaced anteriorly and (usually) inferiorly in relation to the acetabulum. It is often associated with fractures of the femoral head. By James Heilman, MD [CC-BY-SA-3.0], via Wikimedia Commons Fig 4 – Radiograph showing an anterior dislocation of the left hip joint. Rate This Article Arthritis of the Hip - Types, Symptoms, Diagnosis, Treatment ##LOC[OK]## ##LOC[Cancel]## Arthritis of the Hip Arthritis is one of the most common causes of pain in the hip. Arthritis is a progressive disorder, which means that it typically starts gradually and gets worse with time. The term arthritis literally means “inflammation of the joint.” There are different types of arthritis that can affect the hip. The type of arthritis you have may affect your treatment options. Types of Arthritis There are five main types of arthritis that can affect the hip joint.

They are: Osteoarthritis Systemic lupus erythematosus Psoriatic arthritis There is no cure for any type of arthritis, but there are ways to treat the pain and other associated symptoms. Osteoarthritis Osteoarthritis means “arthritis of the bone” and is the most common form of arthritis. It is often described as the result of wear and tear on the joints, which explains why it is more common in older than younger people. The hip joint consists of the ball-shaped end of the thigh bone (femoral head) which fits into the hip socket (acetabular socket). The inside of this ball-and-socket joint is lined with smooth cartilage to help the joint move easily. If this smooth cartilage wears away, the remaining rough surfaces of the ball-and-socket grind against each other, causing pain. Over time, osteoarthritis can degenerate or permanently damage the joint.

Osteoarthritis of the hip (and other parts of the body) has been associated with the following: Structural problems with the hip joint (hip dysplasia, femoroacetabular impingement) Advancing age Previous damage or injury to the hip However, osteoarthritis may develop in people without these risk factors. Figure b Two radiographs of a female patient showing acetabular dysplasia (a shallow hip socket). The patient started to have hip pain when she was 20 years-old (a). This hip dysplasia was not treated and 15 years later she had end-stage osteoarthritis of the hip (b). Note the complete loss of cartilage joint space between the ball and the socket over this 15-year interval. Rheumatoid Arthritis Rheumatoid arthritis is a systemic disorder, that is, it affects your entire body and not just the hip joint. The inflammation is related to an immune system response rather than wear and tear. The hip joint, like other joints in the body, is protected by a special capsule that completely surrounds the joint.

This capsule has a special lining (the synovial lining) and is filled with lubricant (joint fluid) that helps the joint move smoothly. Rheumatoid arthritis typically causes a swelling of the synovial lining. This causes pain and swelling, but eventually, rheumatoid arthritis can cause the bone and cartilage of the joint itself to deteriorate. Rheumatoid arthritis can occur in people of all ages, including children (where it is known as juvenile rheumatoid arthritis), and is more common in women than men. Unlike osteoarthritis of the hip, which may occur only in one hip, rheumatoid arthritis typically occurs in both hips at the same time (and possibly other joints). Rheumatoid arthritis is also associated with overall weakness and fatigue. Medications to treat rheumatoid arthritis continue to improve. Ankylosing spondylitis Ankylosing spondylitis is a chronic inflammation of the spine and sacroiliac joint (the joint where the spine meets the pelvis) which can sometimes cause inflammation of the hip joint.

Ankylosing spondylitis can occur in people of all ages, including children, and typically starts in a person between the ages of 17 and 35. It is more common in men than women. It is typical for people with ankylosing spondylitis to experience flares, when the condition is worse, followed by periods of remission with mild to no symptoms. Systemic Lupus Erythematosus Systemic lupus erythematosus or lupus is a systemic autoimmune disorder that can affect any part of the body, including the hip joint. If lupus strikes the hip, inflammation and damage to the joint can occur. Lupus can occur in people of all ages but it is most common in women aged 15 to 35. Psoriatic Arthritis As the name sounds, this type of arthritis is related to the skin condition psoriasis. Psoriatic arthritis causes joint pain, swelling, and stiffness and can affect any joint in the body, including the hip. Most people with psoriatic arthritis have the skin condition first (scaly red patches of skin) but it is possible to develop psoriatic arthritis before the skin condition occurs.

Arthritis Symptoms Regardless of the type of arthritis, symptoms of hip arthritis include: Pain in the hip joint that may include pain in the groin, outer thigh, or buttocks Pain that is typically worse in the morning and lessens with activity Difficulty walking or walking with a limp Pain that worsens with vigorous or extended activity Stiffness in the hip or limited range of motion In patients with rheumatoid arthritis or lupus, fatigue and weakness may also occur. Arthritis often occurs in flares with remission, but some people experience a relatively stable level of pain without flares. Any type of arthritis can involve more than one joint in the body, so a person with osteoarthritis of the hands may develop the condition in the hip as well. Rheumatoid arthritis and lupus typically affect both hips at the same time, while osteoarthritis and psoriatic arthritis may occur in one hip but not the other. Diagnosis If you suspect you may have arthritis of the hip, the most important first step is an accurate diagnosis. Dr. Clohisy and his colleagues are experts in arthritis of the hip.

A diagnostic evaluation will likely include the following: Your medical history, including where you experience pain and if you limp at times A physical examination, in particular to see how well you can move the hip Radiographs or X-rays to determine if there are any abnormalities in the joint Blood tests to determine antibodies that may be associated with a specific type of arthritis (only if needed). Treatment The Joint Preservation, Resurfacing and Replacement department will prescribe the type of treatment that is appropriate for your particular type of arthritis and other factors, including your overall health, your age, and your personal preferences. Nonsurgical treatment of arthritis of the hip may include any of the following: Anti-inflammatory medications, such as ibuprofen Corticosteroids, injections to block the inflammation in the joint. Physical therapy or exercise programs to improve flexibility, build up strength, and maintain muscle tone. Swimming, in particular, is an excellent exercise for arthritis sufferers. Some types of arthritis may respond to new categories of drugs known as symptom-modifying antirheumatic drugs (SMARDs) and disease-modifying antirheumatic drugs (DMARDs). These are powerful new drugs, which are not appropriate for everyone with arthritis.

Devices such as canes or walkers to make it easier and safer for you to walk. Lifestyle modifications can also help to reduce the symptoms of arthritis of the hip. These include: Maintaining a healthy weight (and losing weight, if necessary) Appropriate pain management Changing activities to minimize stress on the hip Exercising to build up strength Many people with arthritis with the hip are candidates for surgery. Surgery can help to reduce pain, enhance quality of life, and improve your ability to perform everyday activities with fewer or no restrictions. Total hip replacement may be appropriate if the hip joint is severely damaged Osteotomy surgery may be appropriate in less severe cases. Hip osteotomy surgery cuts and repositions the joint surfaces in such a way that it allows the healthy part of the hip joint to bear most of the body’s weight. Only a select group of patients are candidates for osteotomy surgery. If you are an appropriate candidate for hip surgery, the risks and benefits of your surgical options will be discussed. Important Considerations for People with Arthritis of the Hip There is no cure for arthritis. Typically, it starts gradually and worsens over time. Eventually, all forms of arthritis of the hip may permanently damage the hip joint.

While osteoarthritis is more common in older people, there are forms of arthritis that affect younger people. Fortunately, there are things that can be done to help minimize the effect of arthritis, and we are glad to discuss these option. Arthritis Statistics 22% of the U.S. population in 2010 reported some form of arthritis Among adults over 65, 50% have some form of arthritis The most common form of arthritis is osteoarthritis Weight loss of just 11 pounds can reduce a woman’s risk of developing knee arthritis by 50% Of working age people (ages 18 to 64), one-third of those who had arthritis reported it limited their ability to work (Statistics from Centers for Disease Control and Prevention) Request an Appointment BBC Science & Nature - Human Body and Mind - Skeleton Layer Flexibility: Joints enable your body to move Ball and socket joints: Are the most mobile type of joint in your body Saddle joints: Enable you to grasp things Where bones meet Joints are the place where two bones meet. All of your bones, except for one (the hyoid bone in your neck), form a joint with another bone.

Joints hold your bones together and allow your rigid skeleton to move. Fixed joints Some of your joints, like those in your skull, are fixed and don't allow any movement. The bones in your skull are held together with fibrous connective tissue. Slightly movable joints Other joints, such as those between the vertebrae in your spine, which are connected to each other by pads of cartilage, can only move a small amount. Synovial joints Most of your joints are 'synovial joints'. They are movable joints containing a lubricating liquid called synovial fluid. Synovial joints are predominant in your limbs where mobility is important. Ligaments help provide their stability and muscles contract to produce movement. The most common synovial joints are listed below: Ball and socket joints, like your hip and shoulder joints, are the most mobile type of joint in the human body. They allow you to swing your arms and legs in many different directions. Ellipsoidal joints, such as the joint at the base of your index finger, allow bending and extending, rocking from side to side, but rotation is limited. Gliding joints occur between the surfaces of two flat bones that are held together by ligaments.

Some of the bones in your wrists and ankles move by gliding against each other. Hinge joints, like in your knee and elbow, enable movement similar to the opening and closing of a hinged door. The pivot joint in your neck allows you to turn your head from side to side. The only saddle joints in your body are in your thumbs. The bones in a saddle joint can rock back and forth and from side to side, but they have limited rotation. Joints Types, Protection & Location — PT Direct Characteristics of synovial joints The six key characteristics of synovial joints are listed below. 1. Articular cartilage: This is a smooth, white, shiny mass that covers the articular (joining) surfaces of bone. It protects bone tissue and reduces friction (rubbing) between bones when they move. 2. Articular capsule: The articular capsule attaches to the bones near the edge of their articulating surfaces. The capsule is made of strong fibrous tissue and surrounds the joint, adding stability and stopping unwanted material from entering and irritating the joint. The capsule also provides a cavity for synovial fluid to work within. 3.

Synovial fluid: This is a yellowish oily fluid that lubricates the articulating surfaces, forms a fluid cushion between surfaces, provides nutrient for cartilage and absorbs debris that is produced by friction between articulating surfaces. 4. Ligaments: These are strong fibrous bands that join articular surfaces, controlling movement and providing stability. In the adjacent diagram we see the collateral ligaments on each side of the knee which limit side to side movement of the knee and protect it from impact from the side. (Please note that the articular capsule has been removed in this diagram to show the ‘inside’ of the knee joint). 5. Articular discs (meniscus): Some synovial joints such as the knee have menisci. These are made of tough fibrous tissue and their function is to absorb shock and maintain joint stability. They lie between the articulating surfaces and as such protect the surfaces of articulating bone, as seen in the previous image. 6. Bursae: These are found in some synovial joints. They are closed sacs filled with synovial fluid. Their role is to reduce friction that can occur with movement, such as when tendons rub over bones.

An example of bursa is shown in the adjacent diagram of the shoulder (Note the articular capsule has also been removed in this diagram). Factors limiting synovial joint movement Some joints allow virtually unrestricted movement while others are very restricted. The range or degree of movements available at each synovial joint is determined by the following three factors: 1. Joint articulation (how the bones of the joint fit together): If we compare the shoulder and hip joint we can see some key differences in articulation. The shoulder has a very shallow socket which allows the humerus a greater range of movement before it contacts the unmovable object of the scapula. In comparison the deep socket in the hip joint allows far less range for the femur before its movement is stopped by contact with the pelvic bones. 3. Condition of muscles and tendons around a joint: Muscles and tendons also serve to protect joints from excessive movement. Examples can be seen at one of the most mobile joints in the body, the shoulder. Here the extra mobility of the shoulder, due to the shallow socket and lack of bony congruence, requires additional support from the muscles and tendons around it.

The shoulder joint gets this additional support from the rotator cuff muscles and their tendons. This group of muscles provides stability and protection to make up for the lack of ‘bony congruence’, as can be seen in the below image. It’s important to note here that in order to stabilise and protect joints, muscles, tendons and ligaments need to be kept strong and healthy. When they are weak and or have been stretched beyond their normal limit, such as from poor weight lifting technique, their ability to perform these tasks is impeded and injury becomes increasingly likely. Types of synovial joints There are six types of synovial joints which allow varying types and ranges of movement to occur. The variation in the movements at these joints is because of the differences in their characteristics and limiting factors, as previously discussed. The six synovial joints are: 1. Gliding joints: The joint surfaces are flat and of approximately similar length. Movement occurs in a gliding or sliding of one bone against another. Side to side and back and forth movement is allowed with these joints. Examples of gliding joints are: between the carpals of the wrist and between the tarsals of the ankle. 2.

Saddle joints: These joint surfaces resemble a saddle and allow side to side and back and forth movements. An example is the thumb joint shown adjacent between a carpal bone known as the trapezium and the first metacarpal. 3. Hinge joints: The joint surfaces are arranged to allow only back and forth movement such as bending and straightening. Examples of these joints are the elbow where the humerus and ulna join and the knee. 4. Pivot joints: These joints allow only one type of movement, the rotation of one bone on or around another. An example of a pivot joint is the joint between the atlas and axis (C1 & C2) vertebrae, the rotation around each other allows our heads to ‘pivot’ left and right. 5. Ball and socket joints: This type of joint allows side to side, back and forth, and rotational movement. Examples of these joints are the hip or shoulder joints, where the head (ball) of one bone fits into the cavity (socket) of another. 6. Ellipsoid joints: This joint is also known as a ‘condyloid joint’. Ellipsoid joints allow back and forth and side to side movement.

Such joints occur between the metacarpals and phalanges (between the bones of the hand and the bones of the finger) as seen in the adjacent image. Osteoarthritis of the Hip-OrthoInfo - AAOS Copyright 2014 American Academy of Orthopaedic Surgeons Osteoarthritis of the Hip Information on hip osteoarthritis is also available in Spanish: Osteoartritis de cadera Osteoartritis de cadera (topic.cfm?topic=A00608). Sometimes called "wear-and-tear" arthritis, osteoarthritis is a common condition that many people develop during middle age or older. In 2011, more than 28 million people in the United States were estimated to have osteoarthritis. It can occur in any joint in the body, but most often develops in weight-bearing joints, such as the hip. Osteoarthritis of the hip causes pain and stiffness. It can make it hard to do everyday activities like bending over to tie a shoe, rising from a chair, or taking a short walk.

Because osteoarthritis gradually worsens over time, the sooner you start treatment, the more likely it is that you can lessen its impact on your life. Although there is no cure for osteoarthritis, there are many treatment options to help you manage pain and stay active. Anatomy The hip is one of the body's largest joints. It is a "ball-and-socket" joint. The socket is formed by the acetabulum, which is part of the large pelvis bone. The ball is the femoral head, which is the upper end of the femur (thighbone). The bone surfaces of the ball and socket are covered with articular cartilage, a smooth, slippery substance that protects and cushions the bones and enables them to move easily. The surface of the joint is covered by a thin lining called the synovium. In a healthy hip, the synovium produces a small amount of fluid that lubricates the cartilage and aids in movement. The anatomy of the hip. Top of page Description Osteoarthritis is a degenerative type of arthritis that occurs most often in people 50 years of age and older, though it may occur in younger people, too.

In osteoarthritis, the cartilage in the hip joint gradually wears away over time. As the cartilage wears away, it becomes frayed and rough, and the protective joint space between the bones decreases. This can result in bone rubbing on bone. To make up for the lost cartilage, the damaged bones may start to grow outward and form bone spurs (osteophytes). Osteoarthritis develops slowly and the pain it causes worsens over time. A hip damaged by osteoarthritis. Animation courtesy Visual Health Solutions, Inc. Top of page Cause Osteoarthritis has no single specific cause, but there are certain factors that may make you more likely to develop the disease, including: Increasing age Previous injury to the hip joint Obesity Improper formation of the hip joint at birth, a condition known as developmental dysplasia of the hip Even if you do not have any of the risk factors listed above, you can still develop osteoarthritis. Top of page Symptoms The most common symptom of hip osteoarthritis is pain around the hip joint. Usually, the pain develops slowly and worsens over time, although sudden onset is also possible.

Pain and stiffness may be worse in the morning, or after sitting or resting for a while. Over time, painful symptoms may occur more frequently, including during rest or at night. Additional symptoms may include: Pain in your groin or thigh that radiates to your buttocks or your knee Pain that flares up with vigorous activity Stiffness in the hip joint that makes it difficult to walk or bend "Locking" or "sticking" of the joint, and a grinding noise (crepitus) during movement caused by loose fragments of cartilage and other tissue interfering with the smooth motion of the hip Decreased range of motion in the hip that affects the ability to walk and may cause a limp Increased joint pain with rainy weather Top of page Doctor Examination During your appointment, your doctor will talk with you about your symptoms and medical history, conduct a physical examination, and possibly order diagnostic tests, such as x-rays.

Physical Examination During the physical examination, your doctor will look for: Tenderness about the hip Range of passive (assisted) and active (self-directed) motion Crepitus (a grating sensation inside the joint) with movement Pain when pressure is placed on the hip Problems with your gait (the way you walk) Any signs of injury to the muscles, tendons, and ligaments surrounding the hip Imaging Tests X-rays. These imaging tests create detailed pictures of dense structures, like bones. X-rays of an arthritic hip may show a narrowing of the joint space, changes in the bone, and the formation of bone spurs (osteophytes). (Left) In this x-ray of a normal hip, the space between the ball and socket indicates healthy cartilage. (Right) This x-ray of an arthritic hip shows severe loss of joint space and bone spurs. Other imaging tests. Occasionally, a magnetic resonance imaging (MRI) scan, a computed tomography (CT) scan, or a bone scan may be needed to better determine the condition of the bone and soft tissues of your hip.

Top of page Treatment Although there is no cure for osteoarthritis, there are a number of treatment options that will help relieve pain and improve mobility. Nonsurgical Treatment As with other arthritic conditions, early treatment of osteoarthritis of the hip is nonsurgical. Your doctor may recommend a range of treatment options. Lifestyle modifications. Some changes in your daily life can protect your hip joint and slow the progress of osteoarthritis. Minimizing activities that aggravate the condition, such as climbing stairs. Switching from high-impact activities (like jogging or tennis) to lower impact activities (like swimming or cycling) will put less stress on your hip. Losing weight can reduce stress on the hip joint, resulting in less pain and increased function. Physical therapy. Specific exercises can help increase range of motion and flexibility, as well as strengthen the muscles in your hip and leg. Your doctor or physical therapist can help develop an individualized exercise program that meets your needs and lifestyle. Assistive devices. Using walking supports like a cane, crutches, or a walker can improve mobility and independence. Using assistive aids like a long-handled reacher to pick up low-lying things will help you avoid movements that may cause pain.

Medications. If your pain affects your daily routine, or is not relieved by other nonsurgical methods, your doctor may add medication to your treatment plan. Acetaminophen is an over-the-counter pain reliever that can be effective in reducing mild arthritis pain. Like all medications, however, over-the-counter pain relievers can cause side effects and interact with other medications you are taking. Be sure to discuss potential side effects with your doctor. Nonsteroidal anti-inflammatory drugs (NSAIDs) may relieve pain and reduce inflammation. Over-the-counter NSAIDs include naproxen and ibuprofen. Other NSAIDs are available by prescription. Corticosteroids (also known as cortisone) are powerful anti-inflammatory agents that can be taken by mouth or injected into the painful joint. Surgical Treatment Your doctor may recommend surgery if your pain from arthritis causes disability and is not relieved with nonsurgical treatment. Osteotomy. Either the head of the thighbone or the socket is cut and realigned to take pressure off of the hip joint. This procedure is used only rarely to treat osteoarthritis of the hip. Hip resurfacing.

In this hip replacement procedure, the damaged bone and cartilage in the acetabulum (hip socket) is removed and replaced with a metal shell. The head of the femur, however, is not removed, but instead capped with a smooth metal covering. Total hip replacement. Your doctor will remove both the damaged acetabulum and femoral head, and then position new metal, plastic or ceramic joint surfaces to restore the function of your hip. In total hip replacement, both the head of the femur and the socket are replaced with an artificial device. Animation courtesy Visual Health Solutions, Inc. Complications. Although complications are possible with any surgery, your doctor will take steps to minimize the risks. The most common complications of surgery include: Infection Top of page Recovery After any type of surgery for osteoarthritis of the hip, there is a period of recovery. Recovery time and rehabilitation depends on the type of surgery performed. Your doctor may recommend physical therapy to help you regain strength in your hip and to restore range of motion. After your procedure, you may need to use a cane, crutches, or a walker for a time.

In most cases, surgery relieves the pain of osteoarthritis and makes it possible to perform daily activities more easily. Source: National Estimates: Osteoarthritis. Department of Research & Scientific Affairs, American Academy of Orthopaedic Surgeons. Rosemont, IL: AAOS; January 2013. Based on Lawrence RC, Felson DT, Helmick CG, et al. Estimates of the prevalence of arthritis and other rheumatic conditions in the United States. Part II. Arthritis Rheum 2008;58(1):26-35 and U.S. Census Bureau, Population Division, 2011. Top of page Last reviewed: July 2014 AAOS does not endorse any treatments, procedures, products, or physicians referenced herein. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance should consult his or her orthopaedic surgeon, or locate one in your area through the AAOS "Find an Orthopaedist" program on this website. Copyright 2014 American Academy of Orthopaedic Surgeons Related Articles

Question: What kind of joint is the hip?
Answer: Ball-and-socket